Planar antenna is a novel type antenna structure favored by the consumers due to its thinness, flexibility and space saving advantage. Its basic structure is to arrange distributed antenna oscillator structures on a flexible base board or a base board has certain elasticity. Also bearing certain flexibility or elasticity, the antenna oscillator is a flattened metal structure that can deform along with the deformation of the base board without affecting signal reception.
Since its invention, the technology of planar antenna has become increasingly mature. Planar antenna can be applied to various fields, such as European patent application: EP0274592A1, UK patent application: GB2487391A, Japan patent application: JPS5665502A, United States patent application: U.S. Pat. Nos. 3,261,019A, 3,587,105A, 3,815,141A, United States patent: U.S. Pat. No. 6,429,828B1 etc. However, the technical solutions disclosed in these patent documents are limited to receive single frequency band (e.g. UHF or VHF) or simultaneously receive both UHF and VHF with single frequency reception, incapable of receiving multiple frequencies in the same frequency band, therefore the applications are in some degree constrained.
Another disadvantage exists in prior arts is that the layout of the antenna oscillator is not able to improve the strength of the base board. When in use, the flexible base board will easily deform due to the possible external force such as wind force, and the quality of signal reception is in some degree affected by the structural change of the oscillator caused by the deformation of the base board.